Ontology is a formal description of a domain by identifying groups or classes which describes a domain of knowledge along with relationships between concepts. These classes form the foundation of product organization for E-commerce organization.
The Ontology plays an important role because it is generated not just data architecture, but also a search catalog, knowledge architecture, metadata schemas and even the structure of organizations in a company. For a modern E-commerce site, it is the source of all organizing principles.
The best way to set up appropriate categories in taxonomy is by having a good understanding of what is important to a customer. Developing the correct taxonomies and knowledge and information architecture also depends on understanding the lifecycle of their purchase behaviors.